Straits of Florida from west end of Seven Mile Bridge to south of Halfmoon Shoal out 20 to 60 NM Marine Forecast
|Overnight...Northeast To East Winds 20 To 25 Knots. Seas 6 To 10 Feet. Numerous Showers And Isolated Thunderstorms.|
|Monday...Northeast Winds Near 20 Knots. Seas Subsiding To 5 To 8 Feet. Scattered Showers And Isolated Thunderstorms.|
|Monday Night...Northeast Winds Near 20 Knots, Decreasing To 15 To 20 Knots. Seas 4 To 7 Feet. Scattered Showers.|
|Tuesday...Northeast Winds Near 15 Knots. Seas Subsiding To 3 To 5 Feet. Isolated Showers.|
|Tuesday Night...Northeast To East Winds 10 To 15 Knots. Seas 2 To 4 Feet. Isolated Showers.|
|Wednesday...Northeast Winds Near 10 Knots. Seas 1 To 3 Feet. Isolated Showers.|
|Wednesday Night...East Winds 10 To 15 Knots. Seas 2 To 3 Feet. Isolated Showers.|
|Thursday...Northeast To East Winds 10 To 15 Knots. Seas 2 To 4 Feet. Scattered Showers.|
|Thursday Night...East Winds Near 15 Knots. Seas 3 To 4 Feet. Scattered Showers And Isolated Thunderstorms.|
|Friday...East Winds 10 To 15 Knots. Seas 2 To 4 Feet. Scattered Showers And Isolated Thunderstorms.|
|Friday Night...East Winds Near 15 Knots. Seas 3 To 5 Feet. Scattered Showers And Isolated Thunderstorms.|
Synopsis for Keys coastal waters from Ocean Reef to Dry Tortugas: GMZ005|
1025 PM EDT Sun Sep 22 2019
Strong northeast to east breezes will continue across the Florida Keys coastal waters tonight, between high pressure over the Southeast United States and lower pressure over the western Caribbean. The high pressure will gradually weaken Monday through Tuesday, allowing easterly breezes to slowly diminish. Gentle to moderate easterly breezes will prevail from Tuesday night through Friday night, as weak high pressure lingers over the Florida peninsula.
The Approximate Shoreward Edge of the Gulf Stream as of September 21...
- 55 NM South of Dry Tortugas Light...on Loggerhead Key.
- 33 NM South of Cosgrove Shoal Light...off the Marquesas Keys.
- 27 NM South of Sand Key Light...off Key West.
- 21 NM South of Looe Key...off Big Pine Key.
- 18 NM South of Sombrero Key Light...off Marathon.
- 21 NM Southeast of Alligator Reef Light...off Islamorada.
- 20 NM Southeast of Molasses Reef Light...off Key Largo.
- 13 NM East of Carysfort Reef Light...off Ocean Reef.
Area Forecast Discussion|
National Weather Service Key West FL
1018pm EDT Sunday September 22 2019
Currently - A robust continental high pressure system is aligned over the southeastern United States this evening. This is producing a very tight pressure gradient across the forecast area resulting in windy northeast breezes. Drier conditions are gradually bleeding in down across South Florida and the Keys and dew points are now near 70 over South Florida and in the mid 70s in the Keys. This evenings sounding also indicated quite a difference between KEY and MFL profile, with MFL depicting a hefty subsidence inversion based around 800 mb and KEY indicating a much more tropical profile. The upshot of this is, despite the healthy flow, deep shower and thunderstorm activity is dramatically lower than over the past 24 hours. With that said, the coverage of low topped showers remain scattered to numerous.
Short Term Update
The ridge to our north will gradually weaken. As a result, expect a gradual downward trend in northeast to east breezes across the Keys and surrounding waters. Drier air will continue gradually invading southward with dew points falling another degree or three overnight. The combination of both factors will mean the convective downward trend will continue. Only minor changes made in the initial precipitation wording to reflect current trends.
High pressure over the southeastern United States is maintaining a very tight pressure gradient, resulting in fresh to strong northeast breezes across Keys waters. This high will gradually weaken overnight. Expect a downward trend to begin late in the overnight. A small craft advisory remains in effect for all Keys waters.
NOAA Key West FL Office: Watches - Warnings - Advisories
FL...None. GM...Small Craft Advisory for GMZ031>035-042>044-052>055-072>075.